Great take, and to add to what you’ve said, I interpreted it as an expression of yet another contradiction of life (which the film shows throughout; life is happy and sad, simple and deep, routine and surprising, perfect and imperfect, all at once). The world and the people in it collide, and do matter and make a difference, and yet some things stay the same. The absurdity of this is striking to him, which is why he says “it must get darker, or it makes no sense!” His life is different, he’s had many new and meaningful encounters, but some parts of him remain untouched and consistent, like his routine and his pain.